Hammer for mills



July 1940- A. BUKACEK 2,208,892

HAMMER FOR MILLS Filed March 17, 1939 A TTORNEYS.

Patented July 23, 1940 UNITED STATES.

ENT OFFICE 1 Claim.

This invention relates to hammers designed primarily for use inconnection with hammer mills.

Heretofore it has been the practice to form the hammers out of largesections of metal of sufficient hardness to meet the requirements and,in the event of wear or breakage, it has been necessary to replace theentire hammer.

An object of the present invention is to provide a hammer the mainportion of which can be made of relatively soft metal while the strikingsurface or head of the hammer can be formed of a hard metal readilyreplaceable for the purpose of making repairs or replacements andrequiring no special means for fastening the head to the hammer.

With the foregoing and other objects in View which will appear as thedescription proceeds, the invention consists of certain novel details of20 construction and combinations of parts hereinafter more fullydescribed and pointed out in the claim, it being understood that changesmaybe made in the construction and arrangement of parts withoutdeparting from the spirit of the 25 invention as claimed.

In the accompanying drawing the preferred form of the invention has beenshown.

In said drawing:

Figure 1 is a section through a portion of the 30 hammer mill providedwith the present improvement.

Figure 2 is an enlarged side elevation of a hammer.

Figure 3 is a rear elevation thereof.

35 Figure 4. is a section on line 4-4, Figure 3.

It is to be understood that any type of cylinder or concave can be usedin connection with the hammer constituting the present invention and noattempt has been made to illustrate these 40 parts in detail. In Figure1 one form of an apertured concave has been indicated at A, a rotaryshaft has been indicated at B and a series of disks C is connected tothe shaft so as to rotate therewith. These disks C are provided with 45the hammers indicated generally at H and which are pivotally mounted onrods I so as to swing freely relative .to disks C and shaft B.

In the present case each of the hammers is formed of a flat steel stripl which can be suit- 50 ably proportioned and is folded to provide steelstraps 2 which merge at one end to form a substantially cylindrical loop3. An opening 4 is extended through the hammer adjacent to that endremote from loop or sleeve 3 and is adapted to receive the pivot pin Iwhereby a free swinging movement of the hammer is possible. The strapsare joined by welding or by any other means desired.

The hammer head comprises a cylindrical pin 5 5 provided at one end witha head 6 preferably rectangular. This head can be made entirely of hardsteel or its. face only can be hardened or formed with a hardened layerI joined thereto.

Pin or stem 5 can be. inserted readily into the 10 sleeve 3 and it isadapted to so place it that the head 5 will be at the advancing end ofthe pin when the hammer is rotated about the axis of shaft B.

Any desired number of hammers can be used, according to the type of millemployed and the size thereof. In every case the hammer mill shaft Brotates at a high speed and this speed is sufiicient to hold the armsI-I normally extended substantially radially by centrifugal force andobviously the rotation of the hammer in the direction of the arrow shownin Figure 1 will tend I to maintain the pin 5 firmly seated in thesleeve 3. As the outer edges of the heads 6 come into contact withmaterial to be broken up thereby, they will be free to yield backwardlya required amount until resistance is overcome, this yielding actionbeing due to the fact that the arms carrying the heads are pivotallymounted.

Obviously any one of the heads can readily be removed simply by slidingits pin or stem 5 out of its sleeve 3. By making thehead rectangular thesame can be rotated about the longitudinal axis of the pin or stem 5 soas to bring anyone of the edges of the head into active or strikingposition.

What is claimed is:

In a hammer mill a rotatable shaft, a member rotatable with and mountedto swing relative to the shaft, said member comprising a metal stripfolded to provide a cylindrical loop at one end and parallel armsextending from the loop, said arms being joined adjacent to their ends,and apertures at a point remote from the loop, an angular head having aflat face bearing against the loop at one end, a cylindrical stemextending from the center of the head and detachably and frictionallyseated within the loop, said stem and head being adjustable angularlyabout the longitudinal axis of the stem to bring any edge of the head toworking position, the advancing face of the head being harder than theremainder of the head.

ANTON BUKACEK.

